Building a proven IR spotting system.
I will be describing with all details needed a way to build an infrared spotting system identical to the one that I am using, this configuration is the result of multiple tries and errors, lot of time invested and money learning it. I recommend that you follow this procedure and later improve on top of it, when you improve it just "pay it forward" and share your findings.
These are the two critical components needed:
1-LG lcb5100 security camera, buy it new, its regular price is around $174 on Ebay, but sometimes these cameras are sold by less than this price. This is an outstanding camera for IR spotting, I had tested many security cameras but no other come close to this one.
2- Computar motorized lens v10z1618m, these you can get used, usually they are around $100 but if you hunt them you can get it for a lot less.